Engine vibration
Thread Starter
Instructor
Joined: Jan 2008
Posts: 107
Likes: 9
From: Raymond NH
Engine vibration
My '72 350 vibrates between 1600 and 2400 RPM, sitting still. I can feel it in my seat.
I looked at a lot of threads about engine vibration, and can't really find anything specific.
Someone says harmonic balancer, someone else says pilot bearing.
Where should the mark on the harmonic balancer be relative to the stationary mark? Would that even tell me anything?
Any ideas?
pb
I looked at a lot of threads about engine vibration, and can't really find anything specific.
Someone says harmonic balancer, someone else says pilot bearing.
Where should the mark on the harmonic balancer be relative to the stationary mark? Would that even tell me anything?
Any ideas?
pb
Race Director
Joined: May 2006
Posts: 18,604
Likes: 2,541
the harnomic balancer has a metal hub, surrounded by rubber, surrounded by a metal ring. The outer metal rim slips from it's original position because of the rubber failing. If you see the ring has slipped in or out with respect to the central hub the balancer has to be replaced. It has nothing to do with the marks on the balancer or the tab.
Thread Starter
Instructor
Joined: Jan 2008
Posts: 107
Likes: 9
From: Raymond NH
the harnomic balancer has a metal hub, surrounded by rubber, surrounded by a metal ring. The outer metal rim slips from it's original position because of the rubber failing. If you see the ring has slipped in or out with respect to the central hub the balancer has to be replaced. It has nothing to do with the marks on the balancer or the tab.
I'm peering down in there and can't see anything unusual. I'm assuming that the pulley has to be removed in order to see anything loose or misaligned?
pb
Racer
Joined: Feb 2008
Posts: 497
Likes: 0
From: Streator Illinois
Are you sure the vibration is due to engine vibration and not because of some other cause such as tire imbalance?
Terry
Thread Starter
Instructor
Joined: Jan 2008
Posts: 107
Likes: 9
From: Raymond NH
You can put a paint or chalk mark radially from the center out and after driving the car for a while, check to see if the outer pulley has changed position relative to the center hub.
Are you sure the vibration is due to engine vibration and not because of some other cause such as tire imbalance?
Terry
Are you sure the vibration is due to engine vibration and not because of some other cause such as tire imbalance?
Terry
I get the vibration while sitting still. I'll try your suggestion.
pb
Racer
Joined: Oct 2008
Posts: 276
Likes: 5
From: Aptos, CA
Remove your accessory belts and run the engine.
I have a vibe that starts at 1500 rpm and smooths out above 2000 rpm, and it isn't related to my clutch components as I get it with the clutch engaged or disengaged.
I removed my belts and it went away.
Turns out my water pump impeller shaft is wobbling. Something as small as that caused very unsettling vibrations.
I don't know what caused it to fail, but I'm replacing it.
I have a vibe that starts at 1500 rpm and smooths out above 2000 rpm, and it isn't related to my clutch components as I get it with the clutch engaged or disengaged.
I removed my belts and it went away.
Turns out my water pump impeller shaft is wobbling. Something as small as that caused very unsettling vibrations.
I don't know what caused it to fail, but I'm replacing it.
Thread Starter
Instructor
Joined: Jan 2008
Posts: 107
Likes: 9
From: Raymond NH
Remove your accessory belts and run the engine.
I have a vibe that starts at 1500 rpm and smooths out above 2000 rpm, and it isn't related to my clutch components as I get it with the clutch engaged or disengaged.
I removed my belts and it went away.
Turns out my water pump impeller shaft is wobbling. Something as small as that caused very unsettling vibrations.
I don't know what caused it to fail, but I'm replacing it.
I have a vibe that starts at 1500 rpm and smooths out above 2000 rpm, and it isn't related to my clutch components as I get it with the clutch engaged or disengaged.
I removed my belts and it went away.
Turns out my water pump impeller shaft is wobbling. Something as small as that caused very unsettling vibrations.
I don't know what caused it to fail, but I'm replacing it.
pb
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